Signal lines, conductors, or traces (collectively referred to herein as conductors) are used to relay signals between devices on a printed circuit board (PCB), semiconductor chip package, or other electronic device. In certain circumstances, differential signaling is used to relay such signals. Differential signaling is a signaling method in which two complementary (positive and negative) signal components are simultaneously transmitted along a differential conductor pair, one signal component along each of the conductors. Differential signaling generally enhances noise immunity, reduces transient currents, and enhances effective signal transmission.
If the two conductors in the differential conductor pair have a length difference, the simultaneously transmitted signals will arrive at a destination at different times. This difference in arrival time (propagation delay) is referred to as “skew” and may cause, for example, a phase difference between the signals at the destination, referred to as phase skew. If the phase skew is sufficiently severe, reception of the differential signals at the destination becomes difficult.